Combination door safety chain and lock



Sept; 5, 1967 F. E CHAMBERS 3,339,963

COMBINATION DOOR SAFETY CHAIN AND LOCV.

Filed Sept. 8, 1965 .12 1,5 Xi J /6 6 I zy 20 W z 46 M 35 /a INVENTOR. Han/(ll!) 5 Chamber:

' Affa/nay.

United States Patent 3,339,963 COMBINATION DOOR SAFETY CHAIN AND LOCK Franklin E. Chambers, 1115 W. 26th St., Joplin, Mo. 63804 Filed Sept. 8, 1965, Ser. No. 485,692

' 4 Claims. (Cl. 292-264) ABSTRACT OF THE DISCLOSURE This application discloses a combination door safety chain and lock consisting of a chain connected to a door adjacent the free edge thereof by means of a releasable slide latch of the ordinary guard chain type, said chain being extended to a distance from said door greater than arms length and secured to a structural Wall by means adjustable selectively to draw said chain taut to lock the door closed, to introduce a slight degree of slack to permit slight opening of the door but not to permit release of said slide latch, or to introduce a greater degree of slack to permit release of said slide latch.

This invention relates to new and useful improvements in safety appliances for doors, and has particular reference to that class of safety device commonly known as a safety chain, which consists of a slack chain which when operatively engaged connects a door and door frame to permit only a slight opening movement of the door, whereby to permit talking or the passing of small articles through the opening, but not enough to permit a person to pass through the opening. Such safety chains are commonly disengagcable only when the door is completely closed. The device contemplated by the present invention is adapted especially for use in connection with screen doors or storm doors used in connection with the main doors in many houses and other buildings, such screen or storm doors always including panels of screen or glass, or both, often comprising a major portion of the door area. The use of any safety device in the nature of a safety chain in connection with such doors is subject to certain problems, due to the ease with which an intruder may break the glass or punch a hole in the screen, then insert his hand through the opening to release the safety chain. On the other hand, it is often desired to leave the main door open, with the door opening protected only by the screen door, or storm door with screen panels, to provide better ventilation in warm weather. The principal object of the presentinvention is, therefore, the provision of a door safety chain of the character described which. largely solves the difiiculties outlined above.

A specific object is the provision of a door safety chain of the character described which can be readily adjusted either to serve as a standard slack safety chain permitting only slight opening of the door, or to serve as a lock securing the door in a fully closed position.

A further object is the provision of a door safety chain of the character described wherein the means for making the adjustment described above is disposed at such a distance from the door within the building that an intruder cannot gain access thereto simply by pllnohing a hole in a screen panel of the door and extending his hand or arm through the hole.

A still further object is the provision of a door safety chain of the character described wherein the chain may be detached from the door and retracted out of the door opening into the building, so as not to interfere with the operation of the main door, and also to permit full opening of the screen door, but having means whereby said chain cannot be so disconnected by an intruders hand or arm inserted through a hole he might punch in the screen.

Other objects are simplicity and economy of construction, efficiency and dependability of operation, and adaptability for use in connection with many types of doors.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the accompanying drawing, wherein:

FIG. 1 is a fragmentary elevational foreshortened view of the inner surface of a building wall and adjacent portions of a screen door, showing a combination door safety chain and lock embodying the present invention applied thereto, and shown in the locked position,

FIG. 2 is an enlarged fragmentary sectional view taken on line II-II of FIG. 1,

FIG. 3 is a fragmentary sectional view taken on line IIIIII of FIG. 2,

FIG. 4 is an enlarged fragmentary sectional view taken on line IV-IV of FIG. 1, with the control rod advanced to a different position, and

FIG. 5 is a fragmentary sectional view taken on line V-V of FIG. 4.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to a wall of a dwelling or other building, said wall having mounted therein a door frame 4 providing a door opening 6 controlled, so far as the present invention is concerned, by a door 8 having screen panels 10 inset therein. Said screen door opens outwardly in the direction of arrow 12 in FIG. 2, abutting when closed against a shoulder 14 of door frame 2. Said frame may also be equipped with an inwardly opening main door, not shown, which when closed abuts shoulder 16, although said main door is not particularly pertinent to the present invention.

The device forming the subject matter of the present invention includes a rigid metallic slide member 18 affixed to the inner surface of door 8 adjacent the free edge thereof, as by screws 20, and having an internal cavity 22. A wall 24 of said slide member, which is parallel to but spaced inwardly from the door, has formed therein a horizontal slot 26 communicating along its entire length with cavity 22. Said slot is of uniform width except at the end thereof farthest from the free edge of the door, at which point it'is provided with an enlargement 28. Cooperating with slide 18 is a stud 30 adapted to project through slot 26 at right angles to the plane thereof. Said stud has a reduced neck 32 of a diameter to move freely in slot 26, and an enlarged head 34 at its inner end, said head being of a size capable of being inserted through enlargement 28 of slot 26 into slide cavity 22, and to move through said cavity parallel to the slot, but too large to pass through the narrower portion of slot 26. At its outer end, stud 30 is provided with an integral eye 36 in which is engaged one end of an elongated chain 38, said chain preferably being of welded link construction.

In use, chain 38 extends inwardly through door opening 6 and horizontally along the inner surface of building wall 2. Intermediate its ends, said chain passes through a horizontally opening eye member 40 in freely running relationship thereto, said eye member being affixed in a base plate 42 secured to the inner face of door frame 4 adjacent the door opening by screws 43. Said base plate extends to the edge of the door opening, and is bent inwardly to form a flange 44 which protects the edge of the door frame against marring or damage by chain 38. The end of chain 38 opposite from stud 30 is connected in an eye member 46 formed at one end of a straight operating rod 48, which also is disposed horizontally adjacent the inner surface of wall 2, and substantially at the same vertical elevation as slide 18 and eye 40. At the end of rod 48 opposite from eye 46, a handle 50 is afiixed thereto. Intermediate its ends, said rod is supported in a latch device indicated generally at 52, and detailed in FIGS. 4 and 5.

Said latch device comprises a hollow metallic body member having side walls 54 and top and bottom walls 56, is secured at its inner end to wall 2 by screws 58, and is essentially open at its outer end. Each side wall 54 has its outer edge notched to form a cradle 60 (see FIG. 4), said cradles being aligned with and guiding operating rod 48. A pair of levers 62 and 64 are disposed within the latch housing, and extend outwardly from the outer end thereof. Each lever is provided intermediate its ends with a hole 66 which is loosely engaged about rod 48, and which has sharp edges. Each lever is provided at its inner end with a pair of oppositely extending lateral ears 68 (see FIG. 5) which are loosely and pivotally engaged in recesses 70 provided therefor in top and bottom walls 56 of the latch housing, whereby each lever is adapted to be pivoted in a direction generally parallel to rod 48. A helical compression spring 72 is disposed about rod 48 between levers 62 and 64, and biases said levers pivotally apart, normally holding said levers at such an angle to the bar that the edges of holes 66 of said levers are moved into binding engagement with the operating rod, as in FIG. 4. It will be seen that then rod 48 cannot be slid through the latch to the right, since to attempt to do so would merely pull lever 64 into a tighter binding engagement with said rod. Similarly, lever 62 prevents movement of rod 48 to the left. However, if the outwardly projecting ends of levers 62 and 64 are grasped and urged toward each other against the pressure of spring 72 the holes 66 of both levers are moved out of binding engagement with the operating rod, and said rod may be moved freely through the latch in a direction parallel to its axis, but is immediately secured in place whenever levers 62 and 64 are released. This latch device is similar to the ordinary transom latch.

In operation, it will be seen that with the parts positioned as shown in FIG. 1, with stud 30 engaged in slide slot 26 and moved to the end thereof closest the free edge of door 8 and farthest from slot enlargement 28, and with said stud secured in this position by moving operating rod 48 far enough to the left to hold chain 38 taut, then the door 8 is securely locked in a completely closed position. Moreover, an intruder could not gain access simply by punching a hole in one of the screen panels 10 of the door large enough to permit him to insert his hand or arm to gain access to slide 18, as in the case of the usual safety chain, since he still would not be able to move stud 30 to disengage it through slot enlargement 28. Also, he cannot extend his hand and arm through the screen far enough to grasp and release latch device 52, due to the length of chain 38 and the distance of said latch device from the door opening. Spacing said latch device about 2 /2 to 3 feet from the door opening has been found entirely adequate, though this is not critical and may be termed simply as greater than arms length. About the only way the intruder could gain access would be to cut a very large opening in the screen and to enter bodily through the opening. The noise and disturbance caused by such a procedure are sufficient to discourage most sneak thieves.

If latch device 52 is released and operating rod 48 moved all the way to the right, as viewed in FIG. 1, or as far as permitted by handle 50, this introduces suflicient slack in chain 38 that stud 30 may be moved easily the full length of slide slot 26 and removed through enlargement 28 of said slot, so that door 8 may be opened normally. The stud end of the chain then hangs freely from eye 40, in which position it is entirely removed from the door opening so as not to interfere with the operation of the main door which engages shoulder 16 of the door frame. Eye 40 nevertheless holds stud 30 in a position of convenient access for use whenever desired. Eye 40 has the further advantage of holding chain 38 in proper position between said eye and stud 30 even though it may be necessary in some houses to attach latch device 52 to an interior partition wall intersecting the wall 2 in which the door frame is mounted.

At a position of operating rod 48 intermediate the locking and release positions thereof described above, there will of course be positions in which a certain amount of slack is introduced in chain 38, but not enough slack to permit movement of stud 30 all the way to enlargement 28 of slot 26. With the operating rod in such an intermediate position, door 8 can be opened very slightly, such as to permit the passing of papers or other small articles through the opening, but not enough to admit a person or even his hand. Such a position may be indicated by a mark 74 scribed on operating rod 48, which may be indexed at one edge of the housing of the latch device 52, as shown in FIG. 4, whenever this type of operation is desired. In this type of operation, the device operates much the same as an ordinary door safety chain, in that it permits only a slight opening of the door, but differs from the ordinary door safety chain in that it does not permit removal of stud 30 from slide 18 simply by closing the door fully, so that it cannot be released by an intruder simply by punching a small hole in a screen panel and inserting his hand through the hole to reach the slide.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. For use in connection with a building wall having a door opening therein, and an outwardly opening door controlling said opening and having easily broken panels therein, a safety chain device comprising:

(a) a horizontally extending slide member adapted to be affixed to the inner surface of said door adjacent the free edge thereof,

(b) a stud member engaged in and movable longitudinally of said slide member and being disengageable from said slide member only when moved to the end thereof distal from the free edge of the door,

(c) a chain affixed at one end to said stud member and adapted to be extended horizontally therefrom along the inner surface of said building wall in a direction away from said door opening, to a distance greater than arms length from said door opening, and

(d) means for attaching the opposite end of said chain to said wall, said attaching means being adjustable to render said chain taut, whereby said door cannot be opened, or to introduce sufficient slack in said chain that said stud may be moved to the distal end of said slide member and disengaged therefrom, or to introduce a lesser degree of slack in said chain whereby said door can be opened slightly but said stud cannot be disengaged from said slide member.

2. The structure as recited in claim 1, wherein said slide member constitutes a hollow housing having a horizontal slot formed in a wall thereof, said slot extending parallel to the plane of the door and having an enlargement at the end thereof distal from the free edge of the door, and wherein said stud member has a neck portion capable of moving longitudinally of said slot when engaged therein, and an enlarged head capable of being inserted into said housing only through said enlargement of said slot.

3. The structure as recited in claim 1 wherein said means for attaching the opposite end of said chain to said building wall comprises:

(a) a straight operating rod attached at one end to said chain and forming an extension thereof,

(b) a latch housing adapted to be aflixed to said building wall and in which said operating rod is axially slidable,

(c) latch members carried in said housing and operable to grip and hold said operating rod at any point in its sliding movement in said housing,

(d) resilient means carried in said housing and biasing said latch members to their operative positions to grip said rod, and

(e) manual means for rendering said latch members inoperative.

4. The structure as recited in claim 1 with the addition of (a) an eye member adapted to be afiixed to said building Wall adjacent said door opening and through which said chain passes in freely running relationship thereto, said eye functioning to position that portion of the chain between said eye and said stud whereby said attaching means at the opposite end of said chain may be attached to said building in a convenient relationship to said door and slide member.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 3/1907 Germany. 8/1931 Great Britain.

MARVIN A. CHAMPION, Primary Examiner. RICHARD E. MOORE, Assistant Examiner. 

1. FOR USE IN CONNECTION WITH A BUILDING WALL HAVING A DOOR OPENING THEREIN, AND AN OUTWARDLY OPENING DOOR CONTROLLING SAID OPENING AND HAVING EASILY BROKEN PANELS THEREIN, A SAFETY CHAIN DEVICE COMPRISING: (A) A HORIZONTALLY EXTENDING SLIDE MEMBER ADAPTED TO BE AFFIXED TO THE INNER SURFACE OF SAID DOOR ADJACENT THE FREE EDGE THEREOF, (B) A STUD MEMBER ENGAGED IN AND MOVABLE LONGITUDINALLY OF SAID SLIDE MEMBER AND BEING DISENGAGEABLE FROM SAID SLIDE MEMBER ONLY WHEN MOVED TO THE END THEREOF DISTAL FROM THE FREE EDGE OF THE DOOR, (C) A CHAIN AFFIXED AT ONE END TO SAID STUD MEMBER AND ADAPTED TO BE EXTENDED HORIZONTALLY THEREFROM ALONG THE INNER SURFACE OF SAID BUILDING WALL IN A DIRECTION AWAY FROM SAID DOOR OPENING, TO A DISTANCE GREATER THAN ARMS LENGTH FROM SAID DOOR OPENING, AND (D) MEANS FOR ATTACHING THE OPPOSITE END OF SAID CHAIN TO SAID WALL, SAID ATTACHING MEANS BEING ADJUSTABLE TO RENDER SAID CHAIN TAUT, WHEREBY SAID DOOR CANNOT BE OPENED, OR TO INTRODUCE SUFFICIENT SLACK IN SAID CHAIN THAT SAID STUD MAY BE MOVED TO THE DISTAL END OF SAID SLIDE MEMBER AND DISENGAGED THEREFROM, OR TO INTRODUCE A LESSER DEGREE OF SLACK IN SAID CHAIN WHEREBY SAID DOOR CAN BE OPENED SLIGHTLY BUT SAID STUD CANNOT BE DISENGAGED FROM SAID SLIDE MEMBER. 